Incandescent Light Sources Temperature (K) Color at the Peak of the Curve Energy in Visible Spectrum sunlight 5800 Blue 45% photoflood 3400 Orange 30% 100-watt incandescent 2870 Orange 20% 40-watt incandescent 2500 Dark Orange 10% candle flame 1900 Red 3% electric stovetop coil 800 Dark Brown 1% Space used (includes formatting): 1990 / 15000 Part B From the readings above, what can you say about the lighting efficiency of the various incandescent radiation sources? Which are the most efficient in emitting visible light? Support your answer with suitable reasoning. B I U X X2 15 px The 100-watt incandescent has a higher efficiency than the 40-watt incandescent. For the 100-watt one, 2870 x 20% equals 570; for the 40-watt one, 2500 * 10% equals 250. 570 is more than 2 times larger than 250 but 2870 is less than 2500 times 2, so 100-watt incandescent has a higher efficiency. Space used (includes formatting): 303 / 15000 Part C Compact fluorescent (CFL) bulbs provide about four times as much visible light for a given amount of energy use. For example, a 14-watt CFL bulb provides about the same amount of visible light as a 60-watt incandescent bulb. LED lights are even more efficient at turning electrical energy into visible light. Does that mean they are both a lot hotter? Go online and research how fluorescent and compact fluorescent bulbs work. Describe how their operations and their spectra differ from those of incandescent light bulbs. Be sure to record your research sources. BIU X X 2 15 px